PhreeqcUsers Discussion Forum

Reactive Transport => Reactive Transport Modelling => Topic started by: Pak on June 04, 2015, 12:44:25 PM

Title: When coupling iPhreeqc
Post by: Pak on June 04, 2015, 12:44:25 PM
When coupling Phreeqc with a transport software, I have understood that there are mainly two ways.

1) The first one would be to use the Solution_Modify option of iPhreeqc. So first you will run your Phreeqc input such as:
Solution
Cl      Value_Cl
C      Value_C
Ca       Value_Ca
N      Value_N
Equilibrium_Phases
Calcite      log10(SI)     Value_Calcite

And after your transport steps you will just update the new transported master species using will use:

Solution_Modify
-total_h   value_H
-total_o   value_O
-cb      value_cb
-totals   
   Cl      Value_Cl
C      Value_C
Ca       Value_Ca
N      Value_N
   
Run_Cells
-cells X





2) The other approach relies on using every time a Phreeqc’s input. So first you will run the Phreeqc input such as:

Solution
Cl      Value_Cl
C      Value_C
Ca       Value_Ca
N      Value_N
Equilibrium_Phases
Calcite      log10(SI)     Value_Calcite


And after doing a transport step you will run again the update Phreeqc’s input:


Solution
Cl      updateValue_Cl
C      updateValue_C
Ca       updateValue_Ca
N      updateValue_N
Equilibrium_Phases
Calcite      log10(SI)     updateValue_Calcite



Using the first approach you should transport the master species and O, H and charge imbalance using a non-MCD.
Using the second approach what should be transported? I guess the master species, but is there another thing to be transported, using non-MCD?

Thank you
Title: Re: When coupling iPhreeqc
Post by: dlparkhurst on June 04, 2015, 01:18:19 PM
I do not recommend using the second approach. You cannot set the charge balance in the second approach, and the masses of H and O are not well defined. It could probably work in some cases.